Rotary air pump



May 25, 1965 F, J. MOLTCHAN ROTARY AIR PUMP Filed April 16, 1962 l NVEN TOR. Flora J. (6)04 rcwam/ 3,185,385 i ROTARY AIR PUMP 'Floyd J. Moltchan, RD. 1, R0. Box 415,

Canfield, Ohio Filed Apr. 16, 1962, SeraNo. 187,553

Claims; (Cl. 230-137) t This invention relates, in general, to air pumps, and more particularly to an air pump of the type in which air pressure is created by rotating vanes operating under the action of centrifugal force.

As an overall object, the present invention seeks to i provide a small, compact rotary air pump for low volume and low pressure applications, such applications including the inflation of air mattresses, beachballs, rafts, and the like. As will be seen, the invention is also useable for low pressure paint spraying operations and other similar applications.

Another object of the invention is-to provide 'ajnew and improved rotary air. pump capable of producing a greater pressure output than previous air pumps of the same volumetric capacity and horsepower rating.

Still another object of the invention lies in the provision of a rotary air pump which may be operated on either the power available from an automobile electrical system or from a conventional household electrical outlet. Thus, the pump is truly portable in that it may be used anywhere inthe home or plant, or alternatively used outdoors by connecting it, for example, to the cigar lighter receptacle of an automobile.

In accordance with the'invention, i provide a body having a cylindrical cavity therein, a rotatable rotor member eccentrically mounted within the cavity, an A.C.-D.C. motor for rotating the rotor in one direction, radiallyoutwardly extending resilient wanes circumferentially spaced around the rotor with each vane being bent in the direction of rotation of the rotor whereby an outer surface of each vane will slide on the periphery of said cylindrical cavity as the member is rotated, and inlet and outlet ports on opposite sides of the cylindrical cavity with the inlet port being on the side furthest removed from the eccentric axis of the rotor and the outlet port being on Patented May 25, 1965 being such that it will be compressed between the rotor and the inner peripheral surfiace of the cavity as it ap-- proaches the outlet port to provide an effective seal between the vane and the peripheral surface of the cavity.

An important feature of the invention resides in the fact that the vanes are all bent in the direction of rotation of the member on which they are carried. This provides for a better seal between the vanes and the inner peripheral surface of the cavity, thereby facilitating the production of greater output pressures for a given volumetric capacity and horsepower rating.

The above and other objects and features of the invention will become apparent from the following detailed description taken in connection with the accompanying drawings which term a part of this specification and in which: 1 i

FIGURE 1 is a plan or elevational view of the air pump of the invention;

' FIG. 2 is a cross-sectional view taken along line IIII of RIG. 1 showing the rotor of the air pump of the in vention together with its flexible vanes; and

FIG. 3 is a cross-sectional view taken along the same plane as the crosssectional view of FIG. 2, illustrating another embodiment of the invention wherein the vanes are pivotally connected to the rotor rather than integral therewith.

Referring now to the drawings, and particularly to to either a conventional household electrical outlet or to the side nearest the eccentric axis. With this arrangement, an air pocket is formed between successive resilient vanes and the inner peripheral surface of the cavity, the volume of each air pocket decreasing as the vanes advance from the inlet port to the ,outlet port to compress the air in each pocket before it is discharged through the outlet port. Preferably, the rotatable member and the resilient vanes carried thereby are formed from nylon material impregnated with graphite such that the ends of the vanes in contact with the inner peripheral surface of the cavity will be self-lubricating.

.In one embodiment ofthe invention shown herein, cleats are formed on the rotor between successive vanes such that when each vane is pressed inwardly as itappreaches the outlet port of the pump, it will engage a cleat which assists in holding the vane against the inner peripheral surface of the cavity to form an effective seal for the air trapped by the vane.

In another embodiment of the invention, the forward end of each vane is thickened and preferably is provided with an axial opening, the thickness of each forward end an automotive electrical system.

The motor 10 is provided with an outer housing which terminates in a lower annular flange 16. Directly beneath the change 16 is a circular plate 17, and between the plate '17 and a base plate 18 is a circular housing 20. As shown, the base plate 18 is provided with a downwardly-extending annular flange 22; while the base plate 18, housing 20 and plate 17 are secured to the flange 16 by means of circumferential-1y spaced bolts 24.

Referring now to FIG. 2 it will be seen that the housing .20 is provided with a cylindrical cavity 26 having an axis extending parallel to the axis of the shaft 28 for the motor 10. The shaft 28 and the central axis of the cylindrical cavity '26, however, are offset with respect to each other such that a tlexible plastic rotor 30 secured to shaft 28 will rotate within the cavity 26 in eccentric flashion. The rotor 30 comprises a central generally circular portion 3-2 having integral, radially extending vanes 34 thereon. As shown, each vane .34 is bent in the direction of rotation of the rotor 30, indicated by the arrow, and is provided with an outer end which engages the peripheral surface of the cylindrical cavity 26. Preferably, the rotor v 30, including the integral flexible vanes 34, is formed from is closest to the axis of shaft 28 is an outlet port 38. The vanes 34, being resilient, have a natural tendency to spring outwardly and into engagement with the peripheral surface of the cavity 26. This natural tendency, of course, is assisted by centrifugal force on the vanes when the rotor 30 is rotated by motor in the direction of the arrow. It will be appreciated that air pockets are formed between successive vanes on the rotor 30; and as each vane moves from the inlet port 66 to the outlet port 38 it is forced radially inwardly due to the eccentric mounting of shaft 28 within the cavity 26, thereby compressing the air within the cavities as they approach the outlet port 88. It is of primary importance that the vanes 34 be bent in the direction of rotation of the rotor 30 since, in this way, a much more efiective seal is produced between the ends of the vanes and the peripheral surface of cavity 26 than would be the case, for example, if the vanes were bent in the opposite direction. arrangement shown, the air compressed within the air pockets tends to push the vanes radially outwardly; whereas the opposite would be true if the vanes were bent in the opposite direction. Also, the frictional resistance between the vanes and the peripheral wall of cavity 26 tends to move them in a direction opposite to the direction of rotation and, because of the flexible nature of the vanes, causes them to tend to move further outward along the radius of the cavity.

.Provided on the central portion 32 of the rotor 36, and integral therewith, are pressurecleats 40, each of which is interposed between two successive ones of the That is, with the vanes 34. When the vanes are forced radially inwardly as they approach the outlet port 38, they will engage the cleats 40, and these cleats serve to force the vanes radially outwardly and assist in sealing each vane against the peripheral surface of the cavity 26 as they approach the outlet port so as to prevent the escape of air under pressure into the area beyond outlet port 38 in the direction of rotation. The thickness of the rotor 30 is slightly less than the axial length of the cylindrical cavity 26 so that it may rotate freely yet snugly between the plate 17 and the base plate 18.

In FIG. 3 another embodiment of the invention is shown wherein elements which correspond to those shown in FIG. 2 are identified by the same, primed reference numerals. In this case the rotor 30' comprises a generally cylindrical central member 4 2 having a plurality of axially-extending cylindrical slots 44 provided around its circumference. Received Within each of the slots 44 is a resilient vane 46 which, like the vanes 34 of FIG. 2, is preferably formed from a nylon material impregnated with graphite whereby a self-lubricating surface will be formed between each vane and the inner peripheral surface of the cylindrical cavity 26'. Unlike the vanes of FIG. 2, however, the vanes 46 of FIG. 3 are more or less pivotally carried by the central member 42. The end of each vane 46 in FIG. 3 is thickened as at 48 to form a pressure tip. Each pressure tip is provided, as shown, with an axially extending passageway 50 therein. The thickness of each pressure tip 48 is greater than the distance between the periphery of the member 4-2 and the inner periphery of the cylindrical cavity 26' in the area of outlet port 38. Consequently, each pressure tip is compressed as it approaches the outlet port 38' to provide an effective seal between the ends of the vanes 46 and the peripheral surface of cavity 2-6 in much the same manner as did the cleats in the embodiment of FIG. 2.

Thus, by roviding vanes which are bent in the direction of rotation of the rotor 30 or 30', and by providing means for positively pressing the ends of the vanes against the inner peripheral surface of the cavity 26 or 26' as they approach outlet port 38 or 38, a much more effective seal is formed between the tips and the cavity wall such that the pressure and volumetric output capacity of the pump is materially increased over prior art devices of this general type.

Although the invention has been shown in connection with certain specific embodiments, it will be readily apparent to those skilled in the art that various changes in form and arrangement of parts may be made to suit requirements without departing from the spirit and scope of the invention.

1 claim as my invention:

1. Rotary pump means comprising a body having a cylindrical cavity therein, a rotatable member eccentrically mounted within said cavity, means for rotating said member in one direction, radially-outwardly extending resilient vanes circumferentially spaced around the member with one each vane being bent in the direction of rotation of the member whereby an outer surface of each vane will slide on the periphery of said cylindrical cavity as the member is rotated, an inlet port in the side of the cylindrical cavity furthest removed from the eccentric axis of the rotatable member, an outlet port in the side of the cylindrical cavity nearest the eccentric axis of the rotatable member, and resilient finger-like cleats extending radially outwardly from said member and bent in the direction of rotation of said member, said cleats being between the vanes and each adapted to force the forward end of an associated one of said vanes radial-1y outwardly as it approaches said outlet port.

2. Rotary pump means comprising a body having a cylindrical cavity therein, a rotatable member eccentrical- 1y mounted within said cavity, means for rotating said member in one direction, radially-outwardly extending resilient vanes circumferentially spaced around the member with each vane being bent in the direction of rotation of the member whereby an outer surface of each vane will ride on the periphery of said cylindrical cavity as the member is rotated, the axial thickness of said member and the vanes carried thereby being substantially equal to the axial length of the cylindrical cavity whereby pockets are formed around said member between successive vanes, an inlet port in the side of the cylindrical cavity furthest removed from the eccentric axis of the rotatable member, an outlet port in the side of the cylindrical cavity nearest the eccentric axis of the rotatable member, and resilient finger like cleats extending radially outwardly from said member and bent in the direction of rotation of said member, said cleats being between the vanes and each adapted to force the forward end of an associated one of said vanes radially outwardly as it approaches said outlet port.

3. Rotary pump means comprising a body having a cylindrical cavity therein, a rotatable member eccentrically mounted within said cavity, means for rotating said member in one direction, radially-outwardly extending resilient vanes circumferentially spaced around the member with each vane being bent in the direction of rotation of the member whereby an outer surface of each vane will slide on the periphery of said cylindrical cavity as the member is rotated, an inlet port in the side of the cylindrical cavity furthest removed from the eccentric axis of the rotatable member, an outlet port in the side of the cylindrical cavity nearest the eccentric axis of the rotatable member, and resilient cleats on said member for engaging the forward end of each vane as it is pressed inwardly by the peripheral wall of the cavity upon approaching said outlet port, said cleats serving to force the forward ends of the vanes radially outwardly as they approach said outlet port to provide an eifective seal between the peripheral wall of the cavity and each vane.

4. Rotary pump means, comprising a body having a cylindrical cavity therein, a rotatable member eccentrically mounted within said cavity, means for rotating said member in one direction, radially-outwardly extending resilient vanes integral with said member and circumferentially spaced around the member with each vane being bent in the direction of rotation of the member whereby an outer surface of each vane will ride on the periphery of said cylindrical cavity as the member is retated, an inlet port in the wall of the cavity at the point furthest removed from the eccentric axis of the rotatable member, an outlet port in the wall of the cylindrical cavity at the point nearest the eccentric [axis of the rotatable member and displaced 180 with respect to said inlet port, and cleats on the periphery of said member between successive vanes, said cleats being integral with the member and each cleat being adapted to engage the forward end of an associated vane as it is pressed inwardly by the peripheral wall of the cavity upon approaching said outlet port, said cleats serving to force the forward ends of the vanes radially outwardly as they approach the outlet port to provide an effective seal between the peripheral Wall of the cavity and each vane.

5. The rotary pump means of claim 4 wherein the rotatable member and its resilient integral vanes are formed from nylon impregnated with graphite.

References Cited by the Examiner UNITED STATES PATENTS Gregg 230-454 -Srnyser 103-117 M ayus et al. 10 3-117 Abresch 103-117 McIntyre 10'31 17 Kemp 103-140 iMcDuffie 103-117 Smy-ser 91149 Conover 91-439 Carlson 103140 X Great Britain.

, JOSEPH H. BRANSON, JR., Primary Examiner. 

1. ROTARY PUMP MEANS COMPRISING A BODY HAVING A CYLINDRICAL CAVITY THEREIN, A ROTATABLE MEMBER ECCENTRICALLY MOUNTED WITHIN SAID CAVITY, MEANS FOR ROTATING SAID MEMBER IN ONE DIRECTION, RADIALLY-OUTWARDLY EXTENDING RESILIENT VANES CIRCUMFERENTIALLY SPACED AROUND THE MEMBER WITH ONE EACH VANE BEING BENT IN THE DIRECTION OF ROTATION OF THE MEMBER WHEREBY AN OUTER SURFACE OF EACH VANE WILL SLIDE ON THE PERIPHERY OF SAID CYLINDRICAL CAVITY AS THE MEMBER IS ROTATED, AN INLET PORT IN THE SIDE OF THE CYLINDRICAL CAVITY FURTHEST REMOVED FROM THE ECCENTRIC AXIS OF THE ROTATABLE MEMBER, AN OUTLET PORT IN THE SIDE OF THE CYLINDRICAL CAVITY NEAREST THE ECCENTRIC AXIS OF THE ROTATABLE MEMBER, AND RESILIENT FINGER-LIKE CLEATS EXTENDING RADIALLY OUTWARDLY FROM SAID MEMBER AND BENT IN THE DIRECTION OF ROTATION OF SAID MEMBER, SAID CLEATS BEING BETWEEN THE VANES AND EACH ADAPTED TO FORCE THE FORWARD END OF AN ASSOCIATED ONE OF SAID VANES RADIALLY OUTWARDLY AS IT APPROACHES AND OUTLET PORT. 